Headache Over Heels: CT Negative Subarachnoid Hemorrhage

Audience This simulation is intended for MS4 or PGY-1 learners. Introduction Both headache and syncope are common chief complaints in the emergency department (ED); however, subarachnoid hemorrhage (SAH) is uncommon (accounting for 1–3% of all patients presenting to the ED with headache), with near 50% mortality.1–3 It is important to recognize the signs and symptoms that point to this specific diagnosis. Once subarachnoid hemorrhage is suspected, it is critical to understand the appropriate workup to diagnose SAH, depending on the timing of presentation. Once SAH is diagnosed, appropriately managing the patient’s glucose, blood pressure, and pain is important. Educational Objectives By the end of this case, the participant will be able to: 1) construct a broad differential diagnosis for a patient presenting with syncope, 2) name the history and physical exam findings consistent with SAH, 3) identify SAH on computer tomography (CT) imaging, 4) identify the need for lumbar puncture (LP) to diagnose SAH when CT head is non-diagnostic > 6 hours after symptom onset, 5) correctly interpret cerebral fluid studies (CSF) to aid in the diagnosis of SAH, and 6) specify blood pressure goals in SAH and suggest appropriate medication management. Educational Methods High-fidelity simulation was utilized since this modality forces learners to actively construct a differential for syncope, recognize the possibility of subarachnoid hemorrhage, recall the need for lumbar puncture, and talk through management considerations in real time as opposed to a more passive lecture format. Research Methods Twenty emergency medicine residents and medical student learners completed the simulation activity. Each learner was asked to complete an eight question post-simulation survey. The survey addressed the utility and appropriate training level of the simulation activity while also including an open-ended prompt for suggestions for improvement. Results Five PGY3, four PGY2, four PGY1, and seven medical students completed the survey. Ninety-five percent felt that the case was more helpful in a simulation format than in a lecture format. All learners felt that the simulation was an appropriate level of difficulty. Of the comments received, a few learners noted they preferred more complexity. Discussion Overall, the educational content was effective in teaching about the SAH diagnostic algorithm, CSF interpretation, and blood pressure management in SAH. Overall, learners very much enjoyed the activity and felt it was appropriate for their level of training. The most common constructive feedback was to include more specific neurologic findings on physical examination to help guide the student to the diagnosis of SAH. Topics Syncope, subarachnoid hemorrhage, cerebrospinal fluid interpretation, lumbar puncture, intracranial bleed, blood pressure goals and management.


Linked objectives and methods:
Learners are presented with a chief complaint of "syncope" rather than "headache" to encourage them to develop a broad differential for possible causes of syncope, including neurogenic, cardiogenic, and vasovagal (objective 1). In addition, the specific history and physical exam features suggest possible SAH (objective 2), to aid the learner in including this on their differential and to demonstrate some of the classic signs and symptoms such as headache that is worst at onset, family history of aneurysm, and neck stiffness. More obvious neurologic deficits were excluded to maintain a degree of diagnostic mystery. This necessitates further history taking to differentiate between these etiologies and allows the learner to develop a pattern of questioning to use in all future syncope encounters. The patient presented outside the 6-hour time window to force the learner to consider the diagnostic algorithm for SAH as suggested by current ACEP Guidelines (published July 2019), including performing an LP (objective 4). 4 While not included in our initial simulation, it may be beneficial to have learners perform an LP on a mannequin during this point of the case to review and practice the details of this procedure. The learner is then given the opportunity to interpret CSF studies and discuss strategies such as RBC clearance and the ratio of WBCs to RBCs, which meets objective 5. 5,6,7 Lastly, to address objective 6, the patient presents with a blood pressure above the goal range of systolic pressures 140-160 mmHg allowing the learner to recognize the need for antihypertensive medications and decide on the appropriate blood pressure goals and correct antihypertensive medications. 8 Time Required for Implementation: Instructor Preparation: ~5 minutes Time for case: ~15 minutes Time for debriefing: ~10 minutes Recommended Number of Learners per Instructor: [3][4] Topics: Syncope, subarachnoid hemorrhage, cerebrospinal fluid interpretation, lumbar puncture, intracranial bleed, blood pressure goals and management.

Objectives:
By the end of this case, the participant will be able to: 1. Construct a broad differential diagnosis for a patient presenting with syncope 2. Name the history and physical exam findings consistent with SAH 3. Identify SAH on computer tomography (CT) imaging 4. Identify the need for lumbar puncture (LP) to diagnose SAH when CT head is non-diagnostic > 6 hours after symptom onset 5. Correctly interpret CSF studies to aid in the diagnosis of SAH 6. Specify blood pressure goals in SAH and suggest appropriate medication management Background and brief information: You are working in a busy academic emergency department. You walk into the room to see a patient that arrived via private vehicle with a chief complaint of "syncope."

Initial presentation:
The patient is a 55-year-old male presenting after a syncopal episode. The patient states that he was out doing exertional yard work, including lifting heavy bags. His wife found him a few minutes later, lying in the grass. He denies any chest pain, shortness of breath, or tunnel vision prior to losing consciousness. He does endorse maybe feeling lightheaded and notes he had a severe headache prior to falling. He went inside out of the heat and started drinking water. He figured it was just dehydration or heat stroke but was still having headache, neck pain, and nausea, so he decided to come to the emergency department to be evaluated. He denies any vomiting.
How the scene unfolds: The learner should start by placing the patient on cardiac and pulse oximetry monitoring, revealing hypertension with normal heart rate, respiratory rate, and oxygen saturation. The learner should then obtain additional history. If asked more questions about his headache, the patient says he has never had a headache like this. He says it was the worst headache of his life but is somewhat better now. If asked about timing, the patient says the incident happened about seven hours ago (he presented four hours after the event and was in the waiting room for three hours). If asked further review of systems questions, the patient denies hematemesis or melena, tongue biting or urinary incontinence, confusion after falling, or a history of seizures. In addition, he denies any recent medication changes. The learner should then perform a physical exam that reveals an uncomfortable but non-toxic male with normal orientation and cranial nerves exam but nuchal rigidity and reduced neck flexion. The learner should then order diagnostic testing to include at least POC glucose, CBC, CMP, ECG, and CT head. Other optional testing may include troponin, d-dimer, bedside cardiac ultrasound, and vital orthostatic signs. CT head should be interpreted as negative for the acute intracranial process, but the learner should recognize that they cannot adequately rule out SAH based on a negative CT head at over 6 hours after symptom onset, and LP should be performed.
If supplies are available, the learner can perform a lumbar puncture on a mannequin. The learner should then diagnose SAH based on the interpretation of CSF results. Once the diagnosis is made, the learner should recheck the patient's blood pressure, recognize that the systolic blood pressure is higher than the goal of 140-160, and initiate appropriate therapy The learner should start by assessing vital signs. The patient is hypertensive but otherwise stable, not requiring immediate intervention, so the learner should then go on to obtain a full history and physical examination. Physical examination should specifically include a neurologic examination. If the learner fails to ask about headache or neck pain or fails to perform a neurologic examination, the facilitator should complain of headache and prompt the learner to assess neurologic function. Diagnostic studies should then be ordered, including blood glucose, ECG, and non-contrast CT scan of the head at a minimum. If the learner fails to order a CT head, the facilitator should ask, "Are there any tests you would like to order to work up the patient's headache?" or, "What do you make of the patient's headache?" The learner will then receive lab and CT head results (as well as other testing results they ordered). After interpreting the CT head as negative, the learner should suggest a lumbar puncture to further investigate for SAH. If the learner is unfamiliar with this algorithm, they may need to be prompted, "If you are worried about a SAH, but CT head is negative, is there another study you can pursue?" A lumbar puncture can either be performed on a mannequin if able or verbally explained in a step-wise fashion. The learner will be given CSF results that are consistent with SAH. They should then reassess vitals and recognize that the patient is still hypertensive with systolic blood pressure above the goal of less than 140-160. They should then order a titratable intravenous antihypertensive agent. If they do not order medications, the facilitator may ask them what the blood pressure goals are in SAH. Lastly, the learner should contact the Neurology Critical Care team for definitive disposition.